With the development of radio technology, various radio services emerge massively while spectrum resources, on which radio services rely, are limited. Therefore, more and more bandwidths are demanded, which leads to a shortage of spectrum resources. On the other hand, in a conventional spectrum fixed allocation system, the utilization ratio of spectrum resources is low. In a sense, it is such a spectrum allocation system providing fixed allocation to an authorization system that causes the great shortage of spectrum resources.
Cognitive radio technology breaks through the conventional spectrum fixed allocation system to allocate spectrums dynamically among systems, thus improving the utilization efficiency of spectrums. For example, as requirements on daily communication are increasing and simple voice data communication is no longer satisfactory, the proportion of video stream media services are increasing in people's communication life, which requires more bandwidths. International Mobile Telecom (IMT) systems are in unprecedented shortage of spectrums while there are many available spectrum resources for broadcast Television (TV) systems to a great extent, e.g. spectrums of some broadcast TV systems are unused in some areas while spectrums of some broadcast TV systems are covered in some area, but unused in some moments, thus resulting in a low overall utilization ratio. Because of the spectrum fixed allocation system, the unused spectrum resources can be hardly reused, by an IMT system, for example. An IMT system of cognitive radio technology acquires information of a broadcast TV system to take an opportunity to occupy TV White spaces of the broadcast TV system in time and space, thus improving the utilization ratio of spectrums of the broadcast TV system and easing the shortage of spectrums of the IMT system.
When a secondary system takes an opportunity to improve the overall performance of a network by using spectrum resources of a main system, the Quality of Service (QoS) of the main system should also be guaranteed, e.g. a reliable power control mechanism and a main user discovery technology etc. are used to ensure that the main system is not interfered. When a main user to which a spectrum occupied by the secondary system reappears, i.e. when the main user will reuse a spectrum resource original borrowed by the secondary system, in order to strictly ensure that the secondary system will not cause harmful interference to the main user, the secondary system will not use the spectrum and sends a reconfiguration command to a User Equipment (UE) serving on the spectrum to require the UE to exit the corresponding spectrum. Further, the secondary system will search for available idle spectrum resources over again or return to an authorized frequency of the secondary system and notify information of a reconfigured spectrum resource to a UE served by the secondary system to provide services for the UE continuously. Thus, communication needs to be performed among network nodes, key parameters need to be configured, and corresponding processes need to be guaranteed, but there are no feasible methods to solve these problems in the prior art.